Rotary fluid motors are used in many types of heavy machinery. The rotary fluid motors use a hydraulic fluid to actuate the motor. At low temperatures, the hydraulic fluid thickens causing the response time of the rotary fluid motor to decrease.
The rotary fluid motor may incorporate an assist drive mechanism to temporarily rotate the rotary fluid motors during startup at low temperatures, when the flow of the fluid alone is insufficient to maintain operation of the rotary fluid motor. Accordingly, the assist drive mechanism provides initial rotation of the rotary fluid motor during cold weather startup, when the fluid is thickest.